Blue Ash is not a common tree species. It is found in certain spots here and there in its native range of northern & central Illinois, most of Indiana, eastern Ohio, central Kentucky, central Tennessee, most of Missouri, and southeast Kansas. Its compound leaves are 7 to 14 inches long with 7 to 11 leaflets that have sharp teeth on the margin; leaves are dark green and lustrous above and develop a poor to average yellow fall color. It has square twigs where it gets its scientific species name of "quadrangulata." The common name comes from the mucilaginous substance in the inner bark that turns blue when exposed to the air. It usually is found growing in dry or well-drained alkaline soils derived from limestone, but it can also grow in draining wet soils that are acid, with a pH range of 6.5 to 8.5. It is fast growing in lowland sites about 2 feet/year, but medium in upland sites of about 1 to 1.5 feet/year, and lives about 100 to 150 years. It makes a good shade tree with an interesting texture and it is occasionally grown by larger or native nurseries. It has shown resistance to the Emerald Ash Borer, but we'll see whether that continues when the other ashes are depleted.